Organic electroluminescence (referred to as EL, hereinafter) devices are used for a planar light emitting member such as a flat panel display of wall televisions and a back light of displays and the development of EL devices has been widely conducted. As an area of such development, the development of a material used for a light emitting device which emits blue light at a high efficiency and has a long life has been conducted.
For example, a stilbene compound and a device using the stilbene compound are disclosed in EP0610514. However, the disclosed device shows a poor purity of color and has a short life although blue light is emitted at a high efficiency and cannot be practically used.
For practical application of a device as a blue color pixel of a color display, specifically, it is necessary that the y-coordinate of the chromaticity be smaller than 0.18 and the half-life be 10,000 hours or longer.